Automobiles and various other vehicles include various control units for controlling various aspects of the vehicle operation. For example, many vehicles include a steering system, a braking system, a stability control system, and other vehicle control systems. The operation of such vehicle control systems may depend on, among other variables, whether the vehicle is experiencing an understeer condition. A dynamic understeer condition refers to the situation when the vehicle is not turning as expected from the driver's steering inputs, and it is an important concept in vehicle handling and vehicle stability control. However, existing determinations of understeer conditions rely upon calculations at the vehicle level that may be influenced by the understeer condition. In some vehicles, an understeer condition is determined by comparing to a calculated reference yaw rate to the sensor measured yaw rate. In certain other vehicles, vehicle side slip angle is used to determine an understeer condition. However, the calculation of the reference yaw rate and that of vehicle side slip angle may depend upon (among other variables) vehicle speed, which may be influenced by the understeer condition itself. Therefore, the understeer determination results in existing techniques may be skewed.
Accordingly, it is desirable to provide an improved method for assessing understeer for a vehicle. It is also desirable to provide improved program products and systems for assessing understeer for a vehicle.
Furthermore, other desirable features and characteristics of the present invention will be apparent from the subsequent detailed description and the appended claims, taken in conjunction with the accompanying drawings and the foregoing technical field and background.